LUCKNOW, India, Aug 1 (Reuters) - At least 22 people, including a dozen children, drowned on Wednesday in northern India and four were missing after a crowded boat carrying them broke apart and sank, police said. The boat went down in a fast-flowing river in the Maharajganj district of Uttar Pradesh state, where monsoon flooding has left thousands homeless or marooned. "The boat apparently was very old and gave way under the pressure of so many people on board, and the strong river current," senior police officer Prashant Kumar, in Maharajganj, said by telephone. Police said there were 86 people on board and 60 of them were rescued by local villagers and police or swam to safety themselves. Maharajganj district borders Bihar state, where hundreds of thousands of people are stranded or displaced due to the worst monsoon flooding in years.